The transition from a fetus to an air breathing infant is a complex process that in general is successfully accomplished. However a significant number of births often require some type emergent assistance or intervention during this transition. The type of assistance or intervention can vary depending on the situation. Simple stimulation, cardiopulmonary resuscitation or the administration of powerful cardiac drugs such as adrenalin may be needed by way of example.
To determine whether the newborn infant requires resuscitative assistance, the resuscitation team must be able to obtain real time knowledge of a baby's rapidly changing heart rate. Currently physicians and support staff are able to accurately determine the heart rate of fetuses in the womb, and older infants. For example, U.S. Pat. No. 5,749,831 issued on May 12, 1998 to Baker relates to methods and systems for monitoring to assess the health of a fetus being carried within a mother. The methods include sensing fetal heart information using a fetal heart sensor; determining at least one fetal heart rate measure from the fetal heart rate information; detecting umbilical flow information relating to the flow of blood within the umbilical cord; deriving at least one umbilical flow indicator from at least the umbilical flow information; and analyzing the fetal heartbeat measure and umbilical flow measure to produce at least one fetal health parameter.
However with a newborn infant, and especially in a compromised newborn infant, the resuscitation team is limited specifically to physical examination via palpation and auscultation during the critical period of time between clamping of the umbilical cord and the application of electronic monitoring devices. It is well known that currently the quickest and most accurate method to determine a newborn infant's heart rate is to palpate the pulse at the base of the infant's umbilical cord. Alternatively the heart rate may be determined by using a stethoscope and listening to heart beat over the left side of the infant's chest. However the resulting palpation or auscultation derived heart rate measurements are subjectively determined and provide only intermittent information. Furthermore this task is frequently done under very stressful circumstances and is therefore intrinsically prone to error which is magnified when the task is conducted by inexperienced individuals.
The result is that some infants who do not warrant intervention may undergo invasive and potentially deleterious interventions including intubation (i.e. placement of a breathing tube), artificial ventilation and even external cardiac message. Conversely other patients who desperately need these types procedures may not receive them and therefore remain compromised for critical minutes until the resuscitators recognize that the infant is not improving with simple stimulation and oxygen administration.
Prior art devices have tried to provide electronic monitoring in the delivery suite to neonates immediately after delivery. These devices have unfortunately met with limited success. Their limited success is in part due to the blood, mucus, amniotic fluid and vemix caseosa that covers the infant at birth. This must be cleaned from the skin to ensure that any adhesive probes are attached properly and that there is good skin to probe contact allowing for accurate readings. Secondly, some monitoring devices, notably pulse oximetry, depend on good tissue perfusion to ensure an error free signal. Unfortunately, those infants who are in the most serious trouble have the most compromised skin perfusion, so accurate readings are difficult to obtain. Finally in all cases there is a time delay between the moment the umbilical cord is cut, to when the monitors are applied to the infant during which physiological data can not be collected.
Thus an infant umbilical cord monitoring system which is easy and fast to apply to an infant and provides immediate physiological data about the infant is desirable.